The present invention relates to a process for producing a carbon/carbon composite.
Carbon/carbon composite have unique properties such as maintaining high strength and high modulus even at high temperatures above 1,000.degree. C. and having small coefficient of thermal expansion, and their application to components of airospace-craft and devices, brakes and furnace materials are expected.
Carbon/carbon composites are produced by heat treating carbon fibers together with a carbonizable material (matrix) such as phenol or pitch. A carbonaceous pitch, due to a high carbonization yield thereof, is very preferable as a matrix material of a carbon/carbon composite, but it expands in volume during carbonization and forms voids in the matrix, so in the actual production there is repeated a cycle of impregnation and carbonization. On the other hand, in order to attain a high carbonization yield, there has been adopted a method wherein carbonization is performed under hot isostatic pressing (HIP). But, even such HIP is used, it is said that five to eight impregnation-carbonization cycles are usually needed. This repetition of the impregnation-pressure carbonization cycle results in a complicated manufacturing process, thus requiring longer days and increased cost.